 And welcome, just a lady to everybody and welcome to my desk It's a really beautiful day out today. So I did some more outdoor time than indoor engineering time We did a couple of things going First up do want to remind people one last time We're shipping eight of boxes. We're almost done. You want an eight of box? You got to go to eight of box comm and sign up if you signed up and you have to update your address or Payment information because it's like expired. I got to do that this week because after this week it's over We might not have any more left over because we're going to let anyone subscribe and we usually fill up Okay, so on to my desk got a bunch of prototypes in This week, which is great because I already like booked the final PCBs. So first up We've got this optical sensor. You guys remember I did using oh It's kind of nice. You can even see the infrared LED Here and then the receiver here So this breakout you can see when something is reflective here Something shiny is kind of the best Thing here is white the white bottom of this PCB will be Nice when this when this is close about like one to four millimeters away it turns on and It can detect, you know white versus black stripes. This is good for Something being nearby or something reflective is what this silver is going to be There you go. Yeah And then this Couple things I had to change one and realize you really do need to have this running at like over a hundred up to a hundred milliamps to get any reasonable Reflection distance So actually let me get the yeah, it's okay Okay This I ended up picking a 1k Potentiometer, but that's actually mistake because you really this that at what one, you know, milliamp It's like almost nothing's capped in here. So you really want to have See now I have it even more sensitive because I have it at a hundred hundred milliamp Current through the emitter. So I'm going to change this to a 200 ohm Potentiometer and this I changed from 100 ohm to 33 ohm so that means when you're running at five volts you'll get at most 100 milliamps and at least like 10 milliamps or something. So it's a nice, you know in in between number So this is this is nice Worked out quite nicely and I like you know, like I said, I was looking for that right angle sensors This is gonna be good for you know detecting Stuff wanting by very quickly, you know, I wanted to do the index sensing for a Five and a quarter inch disk drive. Okay, so that's that one sensor got done The next thing is I got some samples of Some floppy drives and this one I don't actually know the exact part number because it was you know, the part number was removed This one is the good one that works fine and this one. It's it's an older version and it has a Sony chip here It's like an NPF Sony series and it has this This keyed connector and this one is working great You know, I love this love this one, but then I got this other Get it out of this bin. Oh Floppy drives I got another floppy drive this one and This one This one, okay, so this one Which I can remove It's a little blurry because it's not gonna be Okay, so this one Looks almost identical But you see it has like the sensors exposed here slightly different layout different chips This is an NPF 920 and you know, they're both Sony You can see the Sony logo on on this one and this one is an earlier so it is an earlier Sony one I Think is still here. Anyways, although, I don't know. Maybe it's a little later. I have to find the date codes for these But this one has a It's like dual key, it's kind of weird I don't know why they permitted this so like the floppy connector usually has the notch and the notches at the bottom But this one they actually have the notch at the top also So you could put the connector in upside down. That's not what I did, but it's still this floppy drive is actually not working It's not giving me an index pulse. Although it's getting data out And the motor is definitely spinning So what's weird is that like normally you spin up the motor you immediately get the index pulses coming out And you get data this one the data is coming out but not an index pulse And like I don't understand why and what's weird is I have two of these and they're both not doing it So it's something with this Floppy drive. There's something I have to do to tell it You know, give me the index pulse And my code for the RP2040 that the floppy Board here You know, I'm coding it by hand. I'm kind of following like, you know floppy documentation And so I'm not getting you know, whatever I'm doing. I'm not maybe setting some pin or I have to Gate enable something something. It's not getting the index pulse. So what I have to do is But you know, the seller of this was like, no, I tested in the computer and I'm like, well, I believe you And so I would like to have this floppy drive supported. So what I'm gonna have to do is find or get some like computer with a floppy interface and then Verify it works just like try, you know inserting a disk and see if it boots and then if That if that works then I should sniff it and see like what signals is the flaw is the motherboard floppy controller sending to get this going I do know that like the density and ready pins got like recycled and reused between different drives. So Yeah, interesting. It's like this is an official Sony drive and you can see it's really very similar to this one There's a lot of like you can see it's like they kind of based a lot of stuff similarly, but Yeah, for some reason this is not working. This is the L This actually looks like it's in. Yeah, this is a later one. This one is earlier because of the L ML F 31 It's the F F 34. So I'm assuming it's like three generations later Anyways, okay, so that's some floppy stuff that I was also hacking on And finally before we get to the great search. I got a whole bunch of these cool Drive out the way floppies everywhere Okay, so I got a bunch of the Pico plates and so if you all remember a Few weeks ago. I designed a bunch of boards that would take a Raspberry Pi Pico and You know, this was one that would give you terminal blocks It's this one actually worked quite nicely. Although what's funny is for some reason the ground Trace got deleted between here and so the reset button didn't work, but Other than that, it does work fine. So let me just gently move it A lot of pan jeans, gentle removal. Okay, so this is Um If anything is you got to get it the right way around so this is goes like this And then This one goes like here and then I think I had a demo running on this although it's let's see if it boots into a demo But I had like a little yeah, a little wi-fi temperature humidity demo. So this is connecting to iL and sending humidity and temperature from this HT 20 sensor So it was just like a demo to make sure like, you know, everything was working And then, uh, you know, the reset button works and then you've got, you know, these nice terminal blocks It's actually, you know, looked quite nice in the end. Um, and you know, there's a little bit of a gap because there's kind of It's always a little bit of a gap But it's not too bad. It looks like they're you know, I spaced them just right so that um There was close as you can get pretty much. So this is um You know, I already ordered the PCBs. That's the terminal block. So it's kind of nice because you can just Um connect wires. Oh, and then I did do one change To the terminal block. Can you go to the computer? Forgot I did do one terminal block so Just give you a second I added little wings with, um holes here So that, uh, you can break off the little wings. I thought it would be nice to have a little mounting Mounting ears for this little little guy. Okay. And the next step Uh, came back to the overhead Just wrap up here This is um an underplate that you have like this one Um, it just has a terminal block. This doesn't have terminal blocks. So it's going to be less expensive It's kind of like a very It's got nice mounting holes, but it does have the the double header and what's nice about that As you can see on like this one, you've got one row available. So you're like, oh, I want to You know plug stuff in you can you can plug stuff in on the side So you get like an extra, you know, uh exposure of of all the gpio and then um Two versions one is this prototyping plate And then one is a doubler. So this one the prototype plate is uh uh, you've got the um Reset and stomach qt and then this one Um, you remember I did this it has the battery charger And I remember some of you was like, oh like is it going to bump into the battery case That sorry the battery connector, you know, it doesn't sit all the way flat But it still sits fairly flat and it's actually the reason it's not sitting totally flat Is because of the little, um The connector, this is the pico h and so you see it's got the little plastic piece for the um the pre soldered headers if I remove this And Gently gently and I put on the pico w Okay, so if you see this one, um, it doesn't have the same It actually sits exactly With a little bit of space left over because it doesn't have that little cross plastic piece And um, it sits nice and flat. It does stick out. Yeah, these stick out the bottom But I think that's actually kind of nice because if you wanted you could have like stacking headers that go through so this Let's see if I have a battery handy Okay battery um And then hold on I can plug in the The stomach qt here and then plug in the battery and we'll go go to the great search Um, so this is the same See if I think the battery might be dead is the only thing Oh, yeah, it's totally dead because I left it on overnight Let me charge up the battery Okay, now it's going to be happy again Let's do it You see See let me move this Camera board to Hope it'll work Maybe not weird. Okay. Well live demo happens sometimes um But this version I did test it overnight with the the uh pico w in the battery I was having some weird issue with the sockets Um as well, which could be whites not uh, so we're running right now Um, but this is both these are both good and then I think the only change I made for the final design is Oh, I made the default uh 500 milliamps On so it's by default higher current And then is there another change I made? Oh the enable pin I I added some labels So it's clear which way is is on versus off Like this is off, but like how would you know? So let me Try one more time Okay, um, all right, great. So this is my uh pico um plate hacking And um last but not least the last demo which I haven't I didn't get to uh Yet today is I got the temperature and humidity trinkets This is a samdi 21 with an sht 45 So the idea is you plug it in and you can just have like instant temperature and humidity data Coming into your computer or single board computer or or laptop or whatever Um, so I didn't get I just started like I just saw it in the wires to program it Uh, I haven't gotten any farther. Okay, so that's what's on my desk. I know it's a lot going on But let's go to uh the great search The great search by digiti and adafruit thank you digiti every single week lady at a user power of engineer w s you find things on digiti.com Lady what are you searching for this week? Okay, so this week, um, I was actually working on this sht 45 Trinky, so this is a board that has a usb plug And at samdi 21 and then a temperature humidity sensor and a little neopixel and the idea is that You know, it's it's running circuit python or aduino and it's like Be programmable, but when you plug it in it just immediately gives you temperature and humidity data And people love the sht 45. It's a it's a fairly good precision A fairly good accuracy. I think it's like two percent Uh, humidity accurate and like 0.5 degree centigrade temperature sensor, which is pretty good Um, you just plug it in and and you're ready to go and actually have the prototypes You can go to the overhead real fast again and I can I can show this so Um, this is the the prototype so I already built this Um, the idea is just a reset button You just plug this way to your port and you have a little capacitive touch sensor here if you want But other than that it pretty much just gives you temperature and humidity data and This chip runs cool enough and as long as a neopixel is an on full blast This shouldn't have too much self heating Um, and it comes in a two millimeter thick pcb a little thicker than usual Let's see compared to uh, so this pcb you can see it's a little bit thicker Uh, so that it, uh goes into a usb Uh slot and it it sticks nicely. It has it's not as nice as 2.4 millimeter, but that wasn't available for the prototype pcbs. So um, but As I was doing this I was like, oh, you know It's been a long time since I looked at what available temperature and humidity sensors Are on digikey, uh during the part shortage, of course a lot of parts got discontinued or Changed or or were unavailable Um, but I'm actually glad I did uh, and I'll kind of show you how I searched for this because There's some kind of new interesting sensors that have been released And are available now. So what we want is, uh, let's go to the computer again Um, so in this case I happen to you know already place this part, but you know, I might do another run Uh, I have you know, I stock this component and so it's like easy to pick the sht4 series Um, I want something that can run on three volts And is i squared c so I don't want an analog, you know output sensor. I want a digital only So let's go to digikey and look for humidity sensor So the reason I'm not looking for humidity and temperature is like every sensor has temperature like that's really not a special thing Um humidity sensing them by like measuring capacitance change of this exposed capacitor As it gets damper like the capacitance changes Uh, so, uh, you know a digital sensor will handle all of the calibration for you Um, I know people use like the low cost like dht11 sensors You can even open them up and see that there's a you know this capacitor inside But those are like very uh, low accuracy Low precision but also low cost so we want something a little bit nicer So let's look for an active sensor Um, all these candle humidity sets on issue Um, look at the voltage supply later. We'll want surface mount Um, but I'll pick up also the dash in case um, that doesn't uh include some surface mount parts And then I want it to be normally stocking And just to make it a little easier. I'm not going to show the marketplace products because I just want to see What's for stock sale did you key directly? Um, okay. There's actually quite a few sensors. A lot of these are familiar Um, but while I'm here. I want to change the output type to be I squared C I wasn't going to pick up digital In case like that also means I squared C and then I'll pick up SPI as well But I definitely don't want like this pure analog or PWM or just SPI Although to be honest, there's not that many And then next up, um, you know, I did say I wanted one that would run at 3.3 volts Which is actually kind of like almost all of these Fellows here This is like the only one that isn't so I'll skip that one the west work at 3.3 volts And then So the thing basically, you know, if you sort by let's just put in, you know, 500 for the quantity So you get like a quote at like a Half real If you look at pricing basically What you're going to pay for is speed and accuracy so Uh, the sh t 40 is like a pretty good sensor Um About 2 percent wealth of humidity And I was like, oh, you know, like the sh t 45 if you look so like there's definitely, you know, plus or minus 3% Um as well the sh t 4a, which I guess is like a lower Accuracy, although, you know, the sh t 40 is very inexpensive and I love the sh t 40. Don't get me wrong. It's actually a really good sensor um But let's say we wanted No worse than 2% for The temperature sensors go always going to be very good, but the humidity sensors were you, um And I want, you know, fast response time. I definitely want 30 seconds I think eight seconds at the most Um, so yeah, the sh t 30 and the sh t sorry the sh t 40 and sh t c 3 are both good Um, these are both from uh, since sirion believe yes and sirion and uh, you know, they're they're a good family I'll say that you might want to check the datasheet because The sh t 4 series has um There is different base um Accuracy changes So the sh t 41 is improved and the sh t 45 is even better and a lot of it has to do with Um The typical and max Um error So the typical is what they're going to advertise will be like, oh typical is 2 but the max is kind of what you want to look at Because the max is where it's like, okay, you know, you're typical is 2 Uh percent, but the max is 4 percent Um, so you're like, oh because these these all look like the same You know, like what's the difference between all these? And then if you look at the sh t 45 Which is what I used It's gonna be it's gonna be more expensive. So you're gonna have to scroll down like sorted by price Oh, it's like all the way at the bottom It's not cheap sh t 45 so the sh t 45 um Yeah, you're gonna see this one is plus or minus 1 percent compared to 2 percent And fairly fast response time. So, you know, four seconds So you'll see each one here like this data sheet covers all of them because it's a more recent data sheet That's cool. They're like you can get snappy d parts. Um Sh t 40 typical and max sh t 41. You see the typical is about the same, but then the max is much lower And then the sh t 43 um Also kind of like similar to the sh t 40 And then the sh t 45 is where you're gonna get the absolute best performance. It's like the typical is 1 percent and the max is 2 percent But what was neat is I was like, oh, well, let's actually sort by accuracy So I was like, well, what's the most accurate? Because like I I'm you say sh t 45 and turned out there's actually another family of sensors that just came out I guess from ti never heard of this the hdc 30 I mean it's just but it's like 20 22 But like they probably weren't available to purchase for like, you know a year or two um And this is like a really nice uh sensor with accuracy of plus or minus five percent Very low drift and the temperature sensor Is 0.1 Degree c so this is actually like, you know, I Wasn't expecting to find a new interesting sensor. I go off although of course You know the typical versus the max is also not going to be The same so the typical is 0.5 But the max is two and then you know your best typical rate's going to be um You know under 50 percent so it's like it's not That much different than the shc 45 also at high Humidity it's you know, it starts climbing up to plus or minus three percent Still, uh, you know, it's also uh fairly inexpensive. You know 250 compared to the sht 45 and then looks like I have Some discount pricing. I don't know But uh, yeah, so this is my pick and actually pick I'm going to grab some of these hdc 30 20s It's good to see a new sensor. I think ti they had a couple sensors and um You couldn't get them anymore the hdc series and then it looks like they came back and they're like, okay We have a new improved one. Uh, so like I said, this is you know, 0.5 percent. Typicals is great. Uh, I don't see anything better Um, maybe I'll get a breakout going for this and then we'll also add it to whippersnapper Right, that's the great search. That's great search All righty, that's the show for tonight. Uh, if you hear a little noise in the background, it's gonna be a baby So she's hanging out in the background Watching the show pressing buttons Doing things people see everybody throughout the week. Oh, you know, now my demo works. Oh, you want to shout? Let's go to the overhead Well, no, no, no, no And you just it just died. Sorry. I think there's a loose wire or something. Yeah, do you want to shout? Well, I don't know what happened here It just came up and then I was I think the battery was like dead and it's it's freaking out Nevermind Let's get out of here. I know Because we leave leave all the getting's good. Bye. Bye